Open-hearth furnace



April 29, 1930 2 1,756,484

OPEN HEARTH FURNACE Filied June 25, 1921 5 Shea cs-Sheet 1 HTTOIFNEY WITNESS Aprii 29, 1930. v w, GAST 1,756,484

' OPEN HBARTH FURNACE Q Filed June 25, 1921 5 Sheets-Sheet 2 April 29, 1930. w, s 1,756,484

OPEN HEARTH FURNACE File d June 25, 1921 a Sheets-Sheet s Patented Apr. '29, 1930 UNITED STATES RATE WILLIAM GAST, or PHILADELPHIA, PENNSYLVANIA.

OBEN-HEARTH runnncn g Application filed June 23,

burning prior to entering the heating chamber of the-furnace; to provide means for delivering the air from the respective generators to points exterior of the heating'cham ber where it mixes with the incoming gas'and burns with complete combustion prior to passing through the furnace heating chamber; to provide improved draft conditions in an open hearth furnace; to provide means for promoting complete combustion of the gas products; and to provide other improve-' ments as will hereinafter appear;

In the accompanying drawings,- Fig. 1 represents a sectional elevation of a furnace having embodied therein one form of the present invention; Fig. 2 represents a horizontal section of one end of-the furnace and its adjuncts; and Fig. 3 represents a section on line 3-3 of Fig. 1.

Referring to the drawings, an open hearth furnace 10 having the customary hearth 11 is shown. embodying at two opposite ends one form of the present invention. Since the construction at these endsis preferably similar, this descriptionwill be limited to one end and similar reference numerals applied to like parts at the oppositeiend.

In conjunction. with'the operation of the furnace 10 it isdesirable," to obtain themost advantageous results, to provide a regenerator- -12 of the type shown inmy Patent'No.

1,361,709 wherein the baffle walls 13' of the checker chamber are arranged parallel. to the side walls of the furnace 10 in such a position as to discharge air to the furnace 10, and upon reversal of furnace operation to receive products of combustion from the furnace 10. Flues (not. shown) lead from the customary 1921.1 Serial No. 479,763.

stack and air valve to the respective regenerator's 12 at thetwo ends of the furnace 10 as will be understood. I f

For the purpose of conveying air from a regenerator 12 to the furnace 10, a passage 16 is provided which extends transversely of the end of the furnace 10 and opens into a I vertical shaft 1'? leading'to and in communication with a flame guide throat 18 arranged to discharge into the furnace 10 upon T. OFFICE;

the bath on the hearth '11. The bounding wall 20 of the throat 18 is preferably of tapered form having the smaller end toward the bath and its larger end forming a con- -tinuationof a similarly tapered arch 21' which'forms' a part of the top of the air shaft 17 for a purpose which will presently appear. I

In order to produce the desired combustion, a as nozzle 22 is provided which is mountecf for slidingmovement through the. furnace wall 23 in coaxial relation with the throat 18 so that the supplied gas will be discharged directly-across the air shaft 17 to there mix with the air and produce the desired combustion and intense heating flame. The"discharge end of the nozzle 22 is preferably tapered to'conform to the taper of the partially encircling arch 21 and as it is normally spaced fromthe said arch 21, the air traversing this space will cause, with the nozzle 22, an injector effect to produce an effective velocity as well as athorough mixing of the air and gas. To protect that portion of the nozzle 22 which is exposed to the heat zone. it may be encased in a water jacket 24 in a well known manner and provided with a fire brick lining 25.. The nozzle 22 is mountedfor sliding movement upon a fixed head 26 whichis in communication. with a gas supply conduit 27'and is provided with an outlet port 28 arranged to register with an in; let port 30' formed in the body of the nozzle 22 and communicating with the taper-ed bore 31 of the said nozzle 22. The arrangement is suchthat the quantity of gas,

- mum gas supply, and when conditions require let 34 directedtoward the main nozzle outlet This jet 32 is brought into operationas soon as its inlet 33 is moved into the air shaft 17, and as a result the gas is thoroughly mixed and the burning mixture given the desired velocity. Any desired means may be employed for shifting the nozzle 22 to its opera: tive position, such for example as a-movable rack 36 fixed to the nozzle 22 and meshingwith wheel 38. the latter two members being carried by the head 26 or other fixed part. For the purpose of directing the products of combustion to a regenerator 12, upon re versal of the furnace, the air shaft 17 s eliyes as one channel for the products while ,.two se'pa: rate channels 40 and 41'are arranged to com municate with the-furnacdlOv at opposite sides- I I of the throat 18 and lead downwardly to a lateralPassage 42 which is in communication with the same end of the regenerator 12 as the air passage 16, though inthis'construction an end wall 43 is built up from the bottom of the 'regenerator across the passage 42 to support an arch 44 which jnins a' depending baflie wall 45 across the top portion of the passage 42. This arch 44 is provided with an. opening 46 arranged to be opened and closed by a damper-47 orany other suitable 40 valve means, which maybe operated in any suitable manner. Thisconstruction provides means whereby the products of combustion may enter the regenerator 12 when the valve or damper 47 is open, and whereby all the air is directed from the regenerator to the air shaft 17 when the damper 47 is closed.

regenerator 12 is supplying air to the furnace the daimperfl? is closedso that all the air" passes-through passage 16 and up the shaft 17;;

where it mixes with the gas and'burns prior, to enterin the throat 18 giving a high velocity flame 16 to the tapering inlet about the nozzle 22. The effect is that of an injector and causes the flame-to be'drawn into the throat with a greater acceleration than would be produced by the nozzle, 22 alone. With the auxiliary jet 32 in operation the gas and air are intimately mixed to produce an intense fiaine and a complete burning of theproducts outside of the throat 18 so that the usual losses due'to incomplete combustion are eliminated.

When the furnace is reversed the valve or damper 47 of the regenerator 12, above dea pinion 37 arranged to be actuated'bya hand- 1 "condition.

'ing to the same 'regenerator. -The operation ofthe oppositetend of the fuinace is the same, the products .andair for the respective regenerators being controlled in the usual manner by the stock valve,

E r0m";-the foregoing it will be apparent that aconst'ruction is provided whereby fuel and consequent saving in heat units which are ordinarily lost by radiation With the use of producer gas, a straight, direct well "is supplied directly .to' either-end bf an open hearth furnace with a minimum of travel insulated gas main serves to deliver the gases by the quickest and shortest route to the furnace, so that frictional and temperature -losses are. reduced to 'a'minimum and a considerable fuel saving results,

' In furnaces asjat present in"use,'wh en the gases pass through the regenerators, the checkers are more quickly clogged up with 'theresultthat the furnace commences to slow down, yet it is still maintained in operation even though there' is as much as three to four hours difference th'etime of heats over its ,most eflicientoperating condition.

By the construction embodied in the pres-" ent' invention the life of the regenerator is mate rially prolonged; there isless'clogging ofthe checkersbecausel the air and products 7 travel at an increased-velocity, and it is unnecessaryto employ artificial draft by using:-

any fan blast. Furthermore, the adj ustment of the gas supply relative to the amount I of air, and to the required flame conditions, is

made possible by the provision of the moveble" nozzle and its parts, which are so ar ranged'and designed as to accurately proportion the gas and air for any predetermined -1. In a reverberatory furnace, a furnace at gas port and an air port su ys head having rounding ;tl e gas port and means to longi- .tudinally move the gaspprtreIativeIy to the air port. a

.- 2.- In a reverberatory furnace, a furnace head having a gas port and an air port surrounding-the gas port,'means to move the gas port -axially, the movement of said gas port alsocontrolling the supply of'gas thereto;

3. In a reverberatory furnace, a furnace head having air and gas fiues,- an air ort tapered at its mouth, and receiving air rom said air 1611.9,3. longitudinally movable gas- The maintainin of aconstant I flame having a uniformly high velocity in In the operation of the furnace when one port within the air port and having an openmg controlling the supply of gas thereto from said gas flue. r

4. An end construction for regenerative open hearth furnaces having a throat opening into the hearth, an uptake flue leading to said throat and a member movable across the uptake toward or away from said throat to vary as desired the effective area of the throat, said member having'a port facing the throat, and achannel leading to said port.

5. An end construction for regenerative open hearth furnaces having a throat opening into the hearth, and two uptakes communicating with said throat one of said uptakes having a portion movable toward or away from the throat to vary the efiective opening between the hearth and the other uptake.

6. An' end construction for regenerative open hearth furnaces, having a throat, an uptake with a nozzle end portion extending toward the throat, saidthroat and nozzle being I relatively movable, a, second uptake communicating with the throat and having a portion in rear of thej throat into which the nozzle may be projected, relative movement between the nozzle and throat determining the effective area of -the throat opening between the second uptake and the hearth.

7. An end construction for regenerative open hearth furnaces having a throat opening, into a hearth, an uptake communicating with said throat, a nozzle extending through the wall of the uptake flue and toward the throat,

a stationary uptake communicating with'the nozzle, a carriage supporting the nozzle for movement relatively to the throat, and a seal between the nozzle and the stationary uptake for preventing gas leakage for all positions of the nozzle. v 8. An'end construction for regenerative open hearth furnaces, having a throat, an uptake communicating with said throat, a

no'zzle disposed axially of said throat and adapted to be moved away frdm the throat or toward and into the throat, and a second uptake communicating with the nozzle, the throat and first uptake being in unrestricted communication when the nozzle is in one position and being in communication through an annular opening when the nozzle is in a second position.

Signed at Philadelphia, in the county of, Philadelphia, and State of Pennsylvania,

this 13th day of .June, 1921;

- WILLIAM GAST. 

